<?php
/**
 * FileLogger class file.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @link http://www.yiiframework.com/
 * @copyright Copyright &copy; 2008-2011 Yii Software LLC
 * @license http://www.yiiframework.com/license/
 */

/**
 * CFileLogRoute records log messages in files.
 *
 * The log files are stored under {@link setLogPath logPath} and the file name
 * is specified by {@link setLogFile logFile}. If the size of the log file is
 * greater than {@link setMaxFileSize maxFileSize} (in kilo-bytes), a rotation
 * is performed, which renames the current log file by suffixing the file name
 * with '.1'. All existing log files are moved backwards one place, i.e., '.2'
 * to '.3', '.1' to '.2'. The property {@link setMaxLogFiles maxLogFiles}
 * specifies how many files to be kept.
 *
 * @property string $logPath Directory storing log files. Defaults to application runtime path.
 * @property string $logFile Log file name. Defaults to 'application.log'.
 * @property integer $maxFileSize Maximum log file size in kilo-bytes (KB). Defaults to 1024 (1MB).
 * @property integer $maxLogFiles Number of files used for rotation. Defaults to 5.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @package system.logging
 * @since 1.0
 */
class FileLogger
{
    /**
     * @var integer maximum log file size
     */
    private $_maxFileSize=1024; // in KB
    /**
     * @var integer number of log files used for rotation
     */
    private $_maxLogFiles=5;
    /**
     * @var string directory storing log files
     */
    private $_logPath;
    /**
     * @var string log file name
     */
    private $_logFile='resque.log';


    /**
     * Initializes the route.
     * This method is invoked after the route is created by the route manager.
     */
    public function init()
    {
        parent::init();
        if($this->getLogPath()===null)
            $this->setLogPath(Yii::app()->getRuntimePath());
    }

    /**
     * @return string directory storing log files. Defaults to application runtime path.
     */
    public function getLogPath()
    {
        return $this->_logPath;
    }

    /**
     * @param string $value directory for storing log files.
     * @throws CException if the path is invalid
     */
    public function setLogPath($value)
    {
        $this->_logPath=realpath($value);
        if($this->_logPath===false || !is_dir($this->_logPath) || !is_writable($this->_logPath))
            throw new CException(Yii::t('yii','CFileLogRoute.logPath "{path}" does not point to a valid directory. Make sure the directory exists and is writable by the Web server process.',
                array('{path}'=>$value)));
    }

    /**
     * @return string log file name. Defaults to 'application.log'.
     */
    public function getLogFile()
    {
        return $this->_logFile;
    }

    /**
     * @param string $value log file name
     */
    public function setLogFile($value)
    {
        $this->_logFile=$value;
    }

    /**
     * @return integer maximum log file size in kilo-bytes (KB). Defaults to 1024 (1MB).
     */
    public function getMaxFileSize()
    {
        return $this->_maxFileSize;
    }

    /**
     * @param integer $value maximum log file size in kilo-bytes (KB).
     */
    public function setMaxFileSize($value)
    {
        if(($this->_maxFileSize=(int)$value)<1)
            $this->_maxFileSize=1;
    }

    /**
     * @return integer number of files used for rotation. Defaults to 5.
     */
    public function getMaxLogFiles()
    {
        return $this->_maxLogFiles;
    }

    /**
     * @param integer $value number of files used for rotation.
     */
    public function setMaxLogFiles($value)
    {
        if(($this->_maxLogFiles=(int)$value)<1)
            $this->_maxLogFiles=1;
    }

    /**
     * Saves log messages in files.
     * @param array $logs list of log messages
     */
    public function processLog($log)
    {
        $logFile=$this->getLogPath().DIRECTORY_SEPARATOR.$this->getLogFile();
        if(@filesize($logFile)>$this->getMaxFileSize()*1024)
            $this->rotateFiles();
        $fp=@fopen($logFile,'a');
        @flock($fp,LOCK_EX);
        @fwrite($fp,$this->formatLogMessage($log[0],$log[1]));
        @flock($fp,LOCK_UN);
        @fclose($fp);
    }

    /**
     * Rotates log files.
     */
    protected function rotateFiles()
    {
        $file=$this->getLogPath().DIRECTORY_SEPARATOR.$this->getLogFile();
        $max=$this->getMaxLogFiles();
        for($i=$max;$i>0;--$i)
        {
            $rotateFile=$file.'.'.$i;
            if(is_file($rotateFile))
            {
                // suppress errors because it's possible multiple processes enter into this section
                if($i===$max)
                    @unlink($rotateFile);
                else
                    @rename($rotateFile,$file.'.'.($i+1));
            }
        }
        if(is_file($file))
            @rename($file,$file.'.1'); // suppress errors because it's possible multiple processes enter into this section
    }

    /**
     * Formats a log message given different fields.
     * @param string $message message content
     * @param integer $level message level
     * @param string $category message category
     * @param integer $time timestamp
     * @return string formatted message
     */
    protected function formatLogMessage($message,$time)
    {
        return @date('Y/m/d H:i:s',$time)." $message\n";
    }
}
